Fluoroformic Acid Anhydride, FC(O)OC(O)F

Abstract

The missing link in the family of compounds FC(O)OxC(O)F (x=0, 1, 2, 3), the anhydride of fluoroformic acid (see picture), has been isolated in pure form and characterized. FC(O)OC(O)F is stable at room temperature for several days in a glass cell with a well conditioned surface.

Bis(fluoroformyl)trioxide, FC(O)OOOC(O)F

“…After the first IR spectroscopic evidence for FC(O)OOOC(O)F and FC(O)OC(O)F by photolysis of oxalyl fluoride in the presence of oxygen in a long-path IR cell, [10] we were able to prepare the more stable fluoroformic acid anhydride on a preparative scale and to characterize it comprehensively. [11] Herein we report the synthesis, characterization, and structure of bis(fluoroformyl)trioxide, which can be viewed as the anhydride of the unknown peroxyfluoroformic acid. It is the second, but most simple example of a chainlike acyl trioxide after CF 3 OC(O)OOOC(O)OCF 3 , whose structure is still unknown.…”

Synthesis and properties of trifluoromethoxyl fluoroformyl anhydride, CF3OC(O)OC(O)F

“…The synthesis and characterization of the new asymmetric anhydride CF 3 The conformational analysis performed using the B3LYP/6-311+G* hybrid method indicates that the s-s-s conformer is the most stable one, and that at room temperature the populations of the s-s-s, s-a-s, and s-s-a rotamers could be appreciable. The mid-IR experimental spectrum was simulated using the frequencies obtained from the B3LYP calculations for the three rotamers.…”

“…The conformational space of CF 3 Table 1. Table 1 shows the absolute (Hartree units) and relative plus ZPE (kcal mol À1 ) energies of the most stable conformer as well as the relative population at 273 K. Fig.…”

“…2 depicts the structure of the most stable calculated conformer. Bond lengths and angles are presented in Table 2 together with the experimental data available for the two related symmetrical anhydrides CF 3 for the symmetric molecules the bands are at 1168 and 1057 cm À1 and the asymmetric is at 1116 cm À1 . This effect can be thought of as a transition of properties going from one to the other symmetric anhydride through the asymmetric one.…”

Bis(trifluoromethyl)dicarbonate, CF3OC(O)OC(O)OCF3

“…and assuming similar rate constants and zero activation energies (as expected for a radical recombination reaction) it follows, that reaction (8) is the most probable followed by reaction (10) [11]. In this case it is possible to carry out the reaction at higher temperatures because FCO 2 radicals do not decarboxylate as fast as CF 3 OCO 2 .…”